Australia's refusal to send a warship to the Red Sea has been heavily criticised by the federal opposition but it's been revealed the coalition made a similar call two years ago.
In recent months, the United States asked Australia to join an international campaign against Houthi rebels attacking civilian ships.
The US request was rebuffed, with the Albanese government deploying Defence personnel instead.
The coalition condemned the decision, saying Australia was "missing in action" in the Middle East.
It emerged on Tuesday the Morrison government reached a similar conclusion in February 2022.
The commander of the US-led Combined Maritime Forces wrote to the Australian Defence Force to seek assistance with establishing a task force to tackle drug and weapon smuggling.
The request encouraged Australia's participation through staff or sea or air assets as well as a call to allocate any units transiting the Red Sea in associated support or direct support.
Two months later, just after a federal election was called, the ADF's chief of joint operations replied.
They thanked the Combined Maritime Forces for the invitation but explained Australia's contribution to the region could not be increased.
"Australia remains committed to supporting regional stability and maritime security in a region critical to global trade and prosperity," Lieutenant General Greg Bilton wrote, in correspondence seen by AAP.
"Given our considerable commitments, both domestic and in the Indo-Pacific, we are not able to increase our current contribution."
Opposition Leader Peter Dutton was approached for comment after the correspondence came to light. He was defence minister in early 2022.
Mr Dutton referred questions to the Department of Defence and declined to comment on whether he was involved.
The department confirmed the chief of joint operations declined the 2022 request but did not respond to questions about ministerial input.
Opposition defence spokesman Andrew Hastie said he was not aware of the 2022 request, but maintained the rage against the more recent refusal.
"The situation has changed completely," he told the ABC.
"We have Iranian-backed Houthi rebels firing ballistic missiles, cruise missiles, and loitering munitions at ships."
Australian Associated Press